Lump Sum vs Annuity Calculator: How to Use It
The lump sum vs annuity decision turns on longevity, investment discipline, and what you're giving up either way. This calculator quantifies the trade-off: implied IRR, break-even year, 30-year comparison at 5-year intervals, and bear, base, and bull scenario analysis so you can see where the conclusion is sensitive to assumptions.
What this calculator does
The Lump Sum vs Annuity Calculator takes your lump sum offer, monthly annuity amount, COLA selection, assumed investment return, and current age and produces the implied annuity IRR, the break-even year, a year-by-year comparison of cumulative annuity payments against lump sum portfolio value at years 10 through 30, and three scenario cards showing who wins in bear (4%), base (6.5%), and bull (9%) return environments.
The implied IRR is the key number. It's the rate of return the annuity is implicitly earning against the lump sum. If your expected investment return exceeds the IRR, the lump sum wins. If the IRR exceeds your expected return, the annuity wins. Most decisions aren't that clean because the answer depends on how long you live, but the IRR gives you a clear hurdle rate to reason from.
For pension buyout offers from corporate plans (GM, Ford, Lockheed Martin, and others), the lump sum your employer offers is calculated using the IRS Section 417(e) minimum present value segment rates: three rates that discount your projected payment stream across three time horizons. When those segment rates rise, lump sums fall, and vice versa. This calculator lets you evaluate any offer against the present value at your own assumed return, so you can see whether the offer is above or below actuarial value given your investment expectations.
What each input means
Lump sum offer
The one-time cash amount your pension plan is offering in exchange for permanently giving up the monthly annuity. Enter the exact dollar figure from your retirement offer letter or pension statement. If you haven't received a specific offer and want to evaluate what a fair lump sum should be, use the present value output as the benchmark. A lump sum below the calculated present value at your return assumption means the offer is below actuarial value at that rate.
Monthly annuity amount
Your monthly pension benefit if you choose the annuity instead of the lump sum. Use the single-life figure unless you're also modeling survivor coverage. The monthly amount feeds both the IRR calculation and all year-by-year comparisons. For a joint-and-survivor election, enter the post-reduction monthly benefit, not the single-life figure, since that's what you'd actually receive.
Annual COLA on annuity
Select the cost-of-living adjustment that applies to your annuity. The options are none (the correct choice for most private-sector pensions including GM, Ford, and Lockheed Martin), 2% (some state plans use a fixed 2% COLA), 3%, or CPI (approximated at 2.5%). Most private-sector defined benefit pensions pay a fixed monthly amount for life. Federal FERS and CSRS pensions have a CPI-linked COLA. If you select the wrong COLA option, the break-even year and IRR will be materially wrong. When in doubt, check your plan documents.
Assumed investment return
The annual return you expect to earn on the lump sum if you invest it. This is the rate you need to beat for the lump sum to win. A diversified 60/40 portfolio has historically returned 6 to 7 percent annually over 20-year periods. Entering 5% for a conservative assumption and 7% for a moderate one shows you how much the conclusion changes across a realistic return range. The three scenario cards (bear, base, bull) supplement your base case with fixed reference points at 4%, 6.5%, and 9%.
Current age
Your age at the time of the decision. The calculator uses current age to determine the life horizon for the IRR calculation, which runs from your current age to 85 by default, with a minimum of 15 years and a maximum of 35. The life horizon directly affects the implied IRR: a longer horizon gives the annuity more time to accumulate payments, which raises the hurdle the lump sum needs to clear. A 60-year-old faces a 25-year horizon. A 72-year-old faces a 15-year minimum. The break-even analysis runs independently for up to 50 years regardless of the age input.
Understanding the outputs
The implied IRR is the annuity's internal rate of return against the lump sum. It's the discount rate that makes the present value of all future monthly payments exactly equal the lump sum today. If the IRR is 4.8% and you're confident you can earn 6.5% on the lump sum, the lump sum wins at those assumptions. If the IRR is 6.2% and you think 6.5% investment returns are optimistic, the answer gets harder. The IRR frames the decision as a clear comparison: can you reliably beat this rate with an invested portfolio over a 20-to-25-year horizon?
The break-even year is the point where cumulative annuity receipts catch up to the compounding lump sum at your assumed return. If the break-even is year 18 and you're 62, you need to live past 80 for the annuity to win in total dollar terms. If the break-even is year 26, the lump sum is the better financial outcome for anyone with less-than-exceptional longevity at your assumed return.
The 30-year comparison table shows cumulative annuity payments versus lump sum portfolio value at years 10, 15, 20, 25, and 30. This table reveals the shape of the comparison over time. In the early years the lump sum typically leads because the invested capital is growing. In the later years the annuity closes the gap through accumulated monthly payments, especially with a COLA. Seeing where the crossover happens at each scenario return is more informative than the break-even year alone.
The three scenario cards show a 20-year total for annuity payments versus lump sum portfolio value at the bear (4%), base (6.5%), and bull (9%) return rates. If the annuity wins in the bear and base scenarios and only the bull case favors the lump sum, the annuity is the lower-risk choice. If the lump sum wins in all three, the annuity's implied IRR is lower than even a conservative portfolio can earn.
What this calculator doesn't model
The calculator compares cumulative dollar amounts, not utility. Annuity income is guaranteed regardless of market conditions. Lump sum income depends on investment performance, withdrawal discipline, and avoiding permanent impairment from a bad sequence of early returns. A retiree who takes the lump sum and panics during a 40% market drop may lock in a loss that the cumulative comparison never captures. The annuity's value includes not just the dollar amounts but the certainty of receiving those dollars regardless of what markets do.
Tax treatment also matters. Lump sums rolled to an IRA defer taxes until withdrawal. Lump sums taken in cash trigger ordinary income tax in the year of receipt, potentially at a high marginal rate on a large sum. Monthly annuity payments spread the tax liability over many years. The calculator doesn't model taxes. If you're considering a large lump sum outside of a rollover, the tax impact can materially change the comparison.
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Frequently asked questions
What is the implied annuity IRR and what does it tell me?
The implied IRR is the annual return rate at which the present value of all future monthly payments equals the lump sum today. If the IRR is below your expected investment return, the lump sum is the better financial choice at those assumptions. If it's above, the annuity is. The IRR is calculated over a 15-to-35-year horizon based on your age, using 85 as the planning endpoint.
How does a COLA change the comparison?
A COLA increases monthly payments each year, raising the annuity value relative to a fixed lump sum. A $2,500 monthly pension with a 3% COLA pays $4,504 per month by year 24. Without a COLA it stays at $2,500. Over 25 years, cumulative payments with a 3% COLA are roughly 40% larger than with no COLA at the same starting amount. Selecting the wrong COLA option will produce a meaningfully wrong break-even year and IRR.
What is the break-even year?
The year in which cumulative annuity payments catch up to the lump sum's compounding value at your assumed return. Before the break-even, the lump sum holder has more dollars. After it, the annuity has paid out more in total. A typical break-even for a 62-year-old with no COLA falls between year 14 and year 22 depending on the implied IRR and assumed investment return.
What are the bear, base, and bull scenarios?
Three fixed return scenarios: bear at 4%, base at 6.5%, bull at 9%. Each compares cumulative annuity payments against the lump sum portfolio value at the 20-year mark. If the annuity wins in the bear and base cases and only loses in the bull case, the annuity is the lower-risk choice. If the lump sum wins in all three, the annuity implied IRR is below even conservative portfolio expectations.
How do IRS 417(e) segment rates affect my pension lump sum offer?
Corporate pension plans must calculate lump sum offers using the IRS Section 417(e) minimum present value segment rates: three interest rates that discount projected payments across months 1-60, months 61-240, and beyond month 240. Most plans use the prior November rates. When segment rates rise, lump sums shrink. A 1% increase across all three segments typically reduces a lump sum by 8 to 15 percent depending on your age and benefit size. This is why two retirees with identical monthly benefits can receive offers that differ by tens of thousands of dollars based purely on when they retire.
When does the monthly annuity make more sense than the lump sum?
The annuity tends to win with strong family longevity, no other guaranteed income, a dependent spouse who needs survivor coverage, or limited investment confidence. The lump sum tends to win with below-average life expectancy, no survivor need, investment discipline to stay the course through volatility, and a realistic expectation of earning above the annuity implied IRR.